Time: 947 AM Mon May 4, 2020 Forecaster: Justin Brooks

Heavy Precipitation Outlook
Flash Flood Prediction Program

SLIGHTLY COOLER TODAY WITH A CHANCE FOR EASTERN DISTRICT ISOLATED THUNDERSTORMS THIS AFTERNOON
-Overnight and early morning rain showers have kept temperatures cool this morning before high temperature reach the upper 60's to around 70 today. Skies have cleared this morning out on the plains, with some light scattered rain showers still possible, mainly along the foothills, with a possibility of a few rain showers making their way out onto to the plains through the morning.
-A weak disturbance will move through this afternoon resulting in a slight chance for scattered rain showers/isolated thunderstorms, although most storm activity will be limited to areas east of I-25. Best chance for storms will be from 2pm to 6pm as skies begin to clear out this evening.
-Any rainfall today should remain minimal, if it does produce, with no flood threat for the District.
STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.1" of rain. Moderate to strong thunderstorms will have the potential to produce 0.10-0.25" of rain in 10-30 minutes.

WORST CASE SCENARIO: Moisture levels at the surface remain elevated and a surface wind convergence line, or an outflow boundary sets up over the District allowing for stronger and slower moving thunderstorms to develop with the potential to produce rainfall rates of 0.25-0.50" in 10-30 minutes.

A LOOK AHEAD: High-pressure starts to build Tuesday resulting in drier conditions over the next few days. Temperatures will increase into the mid to upper 70's Tuesday through Thursday before a cold front moves in overnight Thursday. Temperatures Friday will remain cool, in the low 60's, with a chance for rain showers/thunderstorms Friday afternoon and into Friday evening.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 200 PM TO 600 PM
Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE
Arapahoe 200 PM TO 600 PM
Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE
Boulder 200 PM TO 600 PM
Trace (30%) to 0.1" (10%) to 0.3" (5%) NONE
Broomfield 200 PM TO 600 PM
Trace (30%) to 0.1" (10%) to 0.3" (5%) NONE
Denver 200 PM TO 600 PM
Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE
Douglas 200 PM TO 600 PM
Trace (30%) to 0.1" (10%) to 0.3" (5%) NONE
Jefferson 200 PM TO 600 PM
Trace (30%) to 0.1" (10%) to 0.3" (5%) NONE
Foothills above 6500ft      
Boulder 200 PM TO 600 PM
Trace (30%) to 0.1" (10%) to 0.3" (5%) NONE
Douglas 200 PM TO 600 PM
Trace (30%) to 0.1" (10%) to 0.3" (5%) NONE
Jefferson 200 PM TO 600 PM
Trace (30%) to 0.1" (10%) to 0.3" (5%) NONE
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.